Shiite Houthi militia withdrew from Yemeni President Abd Rabbuh Mansour Hadi's palace in his former southern stronghold Aden early Friday after overnight air raids by the Saudi-led coalition, a senior official said.

The militiamen had seized the hilltop complex a day earlier after fierce fighting with supporters of Hadi, who has taken refuge in Saudi Arabia.

"The Houthi militia and their allies withdrew before dawn from the al-Maashiq palace," said the official in Aden, who did not want to be named.

Under pressure from pro-Hadi fighters, the Houthi militiamen retreated to the nearby central district of Khor Maksar.

The militias of Saleh and Alhouthi are committing crimes against humanity in Aden. They will not escape punishment.

Earlier, Nobel Peace Laureate Tawakul Karman said that "militias of Saleh and Houthi are burning Aden," as a number of videos circulated online purportedly showing buildings being burnt in the southern city.

Yemeni troops recapture Ad Dali, Shabwah provinces

The development came as the southeastern province of Ad Dali and the central province of Shabwah have been retaken by troops backing President Hadi, a Saudi military official said on Thursday.

Ahmed al-Asiri, the spokesman for a Saudi-led coalition launching airstrikes against positions of the Shiite Houthi militia, added that the members of pro-Hadi groups and army troops loyal to the incumbent president controlled the two provinces.

He noted that coalition warplanes targeted militants affiliated with the Houthis, who were escaping the two provinces on their way to the southern city of Aden.

For the past week, Saudi Arabia and its Arab allies have pounded Houthi positions across Yemen.

Riyadh says its anti-Houthi campaign comes in response to Hadi's appeals to "save the [Yemeni] people from the Houthi militias".

Islah backs Saudi-led campaign in Yemen

Meanwhile, the Islah Party, the political arm of Yemen's Muslim Brotherhood movement, has declared support for the Saudi-led military campaign launched against the Shiite Houthi militia.

"We hope that the operation would save the country from the crisis instigated by the Houthis and their allies, who bear full responsibility for the outcome of this campaign," the party said in a statement late Thursday night.

"Legitimate President Abd Rabbuh Mansour Hadi was forced to seek support after the Houthis besieged him and seized parts of the country."

Yemen has remained in turmoil since last September, when the Houthis overran the capital Sanaa, from which they have since sought to extend their influence to other parts of the fractious country.

Many Yemenis accuse Iran of supporting Yemen's Houthi militia offensive, a charge that the militiamen and Tehran deny.

Houthis kill 40 deserters

In the southern province of Dhaleh, the Houthis killed 40 people who tried to desert after their commander urged them to lay down their arms because of the intense airstrikes, military sources said.

Meanwhile, Saudi Arabia announced its first casualties since launching the offensive, with one soldier killed and 10 more wounded by gunfire from across the Yemeni border.

At least 44 people - including 18 civilians - were reported dead on Thursday in Aden, as rights groups expressed alarm at civilian casualties.

UN aid chief Valerie Amos said 519 people have been killed and nearly 1,700 injured in two weeks of fighting in Yemen, adding she was "extremely concerned" for the safety of trapped civilians. Air strikes have also been criticised for not taking sufficient care to prevent civilian casualties and damage to civilian infrastructure. MEE's contributor in Sanaa Yousef Mawry has said that many homes and vehicles in the capital have been destroyed.

Diplomats in New York said Gulf countries were locked in tough negotiations with Russia on a UN draft resolution to impose an arms embargo and sanctions on the rebels.